Method and apparatus for treating crude oil



May 2, 1944. G. DE BRETTEVILLE 2,347,877

METHOD AND APPARATUS FOR TREATING CRUDE OIL Filed Oct. 14, 1941 IN VENTOR,

6155a?) defireiib'ville A'ITDRN EYS iiatented May 2, 19M

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METHOD AND APPTlUg FQR TREtTliNG \GRUDE 81L Claims.

from the well, and its general object is to provide.

a simple method'for treating the oil to primarily prevent the escape ofvolatile gases therefrom, the method consisting essentially of bringingabout a material decrease in the temperature of the oil before it is runto storage or a refinery, it being well known that crude oil issuingfrom'the well may have a temperature up to 180 degrees Fahrenheit, andthe temperature is generally increased by passing the oil through adehydrator, consequently the oil retains a relatively high temperatureunder normal conditions, when reaching storage, thus resulting in thevolatile gases that are suspended therein being expelled or liberatedtherefrom, especially in storage, but by the use. of the temperaturelowering and refrigcrating steps of my method, the major portion of thegases are retained or preserved within the oil, thereby making itpossible to produce a better grade of gasoline with less cost.

A further object is to provide an apparatus for carrying out my method,that is simple in construction, inexpensive to manufacture, andextremely eiiicient in use and service.

Another object is to provide an apparatus for the purpose set forth thatincludes means for cleaning the same and particularly for removing waxor the like therefrom, so as to allow free passage of the oil throughthe apparatus.

This invention also consists in certain other features of the method andconstruction of the apparatus, and in the combination and arrangement ofthe several parts thereof to be hereinafter fully described, illustratedin the accompanying drawing and specifically pointed out in the appendedclaims.

In describing the invention in detail, reference will be had to theaccompanying drawing wherein like characters denote like orcorresponding parts, throughout the same, and in which:

The figure is a diagrammatic view of one form of apparatus for carryingout my method.

Referring to the drawing in detail, it will be noted that the apparatusin the form shown includes a dehydration unit made up of an uprightcylindrical container or what X term a dehydration tank 9, that isconnected with the usual gas trap not shown, the latter directlyreceiving the crude oil as it issues from the well. From the trap, theoil is directed to the tank by a pipe line that includes a pair ofupright sections 2 and 3 connected together at their upper ends by ashort section t, and connected to the lower end of the 56 tiwlarly s itpasses through the lower portion inner section 3 is a horizontal section5 which extends into the tank for disposal diametrically thereofadjacent its bottom, and the section 5 is provided with a plurality ofoutlet openings 6 along the length of its upper surface, to allowpassage of the oil into the tank, as indicated by the arrows.

The dehydration unit also includes a heater 1 for heating chemicallytreated water or solution. and rising from the heater is an outlet pipeline ll which includes an upper portion 9 connected to the tank Isubstantially midway the height thereof, while an inlet pipe 10 to theheater extends from the lower end of the tank. By that construction, itwill be obvious that the heated chemically treated water passes throughthe lower portion of the tank and is circulated between the latter andthe heater to bring about separation of well water and foreign matterfrom the oil, so that the latter in a clean condition will rise abovethe normal water level within the tank, as shown.

The precooling unit for the oil includes a cylindrical uprightreceptacle H having upper and lower plates l2 and I3 fixed therein, theupper plate being disposed a considerable distance below the top wall ofthe receptacle, while the lower plate is arranged in close proximity toits lower end for cooperation with the upper plate to provide an oilreceiving chamber. Secured to and disposed between the plates are watertubes H, and the receptacle is in direct communication with the tank Ithrough the medium of a pipe l5 that extends from the tank approximatelyat,

the normal level of the oil and is connected to the receptacle justbelow the upper plate l2.

Disposed in the space above the top of the receptacle and the upperplate i2 is a cold water spray nozzle of a diameter so that the watertherefrom will be sprayed over the entire area of the plate it, toassure that approximately the same quantity of water will pass througheach of the tubes it, and the nozzle is supported in close proximity tothe top wall of the receptacle by a pipe line H which of course supplieswater to the nozzle and from a suitable source of cold water supply.Suitably supported below the receptacle ii in spaced relation thereto isa catch basin it having a concaved bottom and depending centrallytherefrom is an outlet pipe it, with the result it will be seen that anair space is provided between the receptacle and the catch basin, whichtends to create a draft of air within the tubes, or in other wordsaerates the water, parof the tubes. to bring about an increased coolinaction of the oil.

From the precooling unit, the oil is passed to a refrigeration unitwhich also includes a cylindrical upright receptacle having an oil inletchamber 2| secured to and rising from the top wall thereof. Connected tothe chamber 2| is the upper horizontal section 22 of a pipe line thatalso includes a vertical section 23 having a hand control valve 24therein, and a lower horizontal section 25 extends between the verticalsection 23 and the lower end of the precooling unit receptacle The handcontrol valve 24 is disposed between the section 25 and the section 23,to close off the refrigeration unit from the precooling unit, and thevertical section 23 extends below the section 25 for connection with alower horizontal section 26, the latter having connected thereto, anoutlet section 21 for the receptacle 20 and which is secured to thebottom wall of the receptacle 20 in depending relation therefrom, aswell as has a. valve 28 therein for controlling the passage of oil fromthe receptacle 20 to the pipe section 26. A thermometer 29 may besecured to the section 26 to ascertain the temperature of the oilpassing therethrough, as will be apparent.

Suitably supported in the receptacle 20 adjacent to the top wall thereofis a baflle plate 30 for distributing the oil over a refrigeration coil3| mounted vertically in the receptacle 20, the coil having an inletpipe 32 leading from a suitable refrigerating machine, and an outletpipe 33 extending to said machine.

Secured to and rising from the lower horizontal pipe section 26 is'anupright pipe section 34 that has its upper end connected to a gas bypasspipe that will be later described, to prevent a siphoning action takingplace in the apparatus or system, and connected to the upright pipesection 34 is a horizontal section 35 that is disposed on the same levelas that of the pipe I5, and the section 35 has an upright or verticalsection 36 secured thereto and paralleling the lower portion of the pipesection 34, the section 36 having its lower end connected to an outletsection 31 that is connected to the section 26 through the medium of avalve 38, and the section 31 is connected to a pipe line that leads to astorage tank or the like for the oil. A valve 39 I is provided for thesection 31, and a valve 40 is likewise provided between the sections 26and 34.

The upright pipe section 34 not only provides what may be termed a ventfor the apparatus to prevent a siphoning action therein. as above setforth, but retards the flow of the oil through the apparatus, so as tokeep the water tubes |4 covered with oil and receptacle always full ofoil and keep refrigeration coil 3| and the refrigeration receptacle 2|)always full of oil at all times while the apparatus is in use.

In order to prevent the precooling unit from becoming gas locked, Iprovide a by-pass for the gas that conveys the same from the upper endof the section 2, to the inlet chamber 2|, the bypass including a pipeline 4| previously referred to and which extends from the section 2 tothe chamber 22, and a pipe section 32 extends between the pipe line tiand the pipe it, for con veying any gas that may be in the oil as itpasses from the dehydration tank i to the receptacle Any gas thataccumulates within the dehydration tank above the oil therein, is passedto the pipe line 4| by a pipe section 43, that extends from a partition44 adjacent the top wall of the tank l,

- valve 58 is likewise the partition acting to provide a cold waterchamber 45, so that the gases condense when coming in contact with thepartition.

From the structure so far described, and disclosure in the drawing, itwill .be obvious that crude oil from the gas trap, not shown, is passedto the upright section 2 and through the same as well as the sections 3and 5, for disposal within the tank I, to commingle with the chemicallytreated hot water therein, for removing water and foreign matter fromthe oil. The clean oil is then passed to the receptacle through themedium of the pipe I5, where the temperature of the oil is reduced,prior to being acted upon by the refrigeration unit. From the receptacleII the oil passes through the pipe sections 25, 23 and 22, for disposalin the receptacle 20, where its temperature is materially lowered by therefrigeration coils 3|. From the receptacle the oil is passed to storagethrough the medium of the outlet section 21, and the pipe sections 26,34, 35, 36 and 31.

A valve 41 is provided in the vertical pipe section 23, to prevent theoil from passing directly from the precooling unit to the pipe section26, and the latter has an outlet valve or faucet connected to a reducedportion thereof, so that the oil can be tested either before or after itpasses through the refrigeration unit.

It will be further obvious that the apparatus tends to become cloggedwith foreign matter, and particularly wax, parafiln or the like, and inorder to clean the apparatus and to remove the foreign matter therefromto allow free passage of oil therethrough, I provide a cleaning systemwhich includes a motor driven pump 49 having a pipe line 50 connected atits lower end to the pump housing and at its upper end to the tank Iabove the transverse center thereof, the pipe line 50 having a valve 5|therein adjacent its upper end and the pipe line 50 is connectedsubstantially midway its ends to the tank I, by a valved coupling 52. Apipe line 53 has one end connected to the pump housing, and its oppositeend is connected to the outlet section 31, between the valve 39 thereofand the upright section 35. A valve 54 is provided in the pipe line 53.I

By that construction, it will be obvious that any suitable cleaningfluid can be pumped through the apparatus by reverse circulation, andafter the apparatus has been thoroughly cleaned, the fluid is removedtherefrom by pumping clean crude oil therethrough. The apparatus is thenready to be operated in the usual manner, to bring about the lowering ofthe temperature of the crude oil from the well, to prevent escape of thevaluable and desirable volatile gases from the oil, so that the lattercan be refined to yield gasoline of a better quality and at a lowercost.

It will be further noted from the drawing, that the pipe section 34above the section 35 has a valve 55 therein and the vertical branch 55of the gas by-pass pipe line 4|, that leads to the inlet chamber 2|, isalso provided with a valve 51. A provided in the pipe section 42 and theby-pass pipe line 4| is further provided with a valve 58' that is disosed just above the pipe section 2. The valves 55,, 57, 58 and 58' areclosed when the apparatus is being cleaned, to prevent the cleaningfluid from passing through the gas icy-pass pipeline 4|, as will beapparent.

the event the oil is free from water and foreign matter as it comes fromthe well, it is of course not necessary to pass the same through thecleaning solution of the dehydration unit..-

and that solution may be removed from the tank I, but I prefer to passthe oil that comes from the well free from water and in a cleancondition directly to the pre-cooling unit. For that purpose, I providea by-pass pipe 59 that has its inlet end connected to the uprightsection 2 and its outlet end connected to the pipe IS, the latter havinga valve 60 therein between the tank I and the pipe 59, and the section 2is also provided with a valve 6| just above the inlet end of the pipe59. A valve 62 is also provided in the by-pass pipe 59. By thatconstruction, it will be obvious that it is not necessary to pass theclean oil through the dehydration unit and that it can be directlyintroduced within the precooling unit.

While I have stated that my apparatus is connected to the usual gas trapin the production line from the well, to receive the oil after it passesthrough the trap, the apparatus may be connected ahead of the trap torefrigerate the oil before it reaches the trap, as in some instancessuch arrangement will be desirable.

Itis thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction andin the combination and arrangement of the several parts, provided thatsuch changes fall within the scope of the appended claims.

What I claim is:

1. A method of treating crude oil to retain the natural volatile gasestherein, consisting of conveying oil from a well gas trap in a verticalupward and thence downward course, introducing the oil from said courseto the bottom of a dehydration unit for removing well water and otherforeign matter therefrom, conveying the clean oil from the dehydrationunit to the upper portion of a precooling unit, conveying the oil fromthe lower portion of the precooling unit to the top of a refrigerationunit, conveying the oil from the bottom of the refrigeration unit tostorage, bypassing gases liberated from said oil in advance of theprecooling unit to prevent the latter from becoming gas locked, andintroducing the liberated gases into the top of the refrigeration unitto cause absorption thereof with the oil therein.

2. In an apparatus for treating crude oil, a dehydration unit includingan upright tank,

means for circulating chemically treated hot water through the lowerportion of the tank, a pipe line adapted for receiving oi1 as it issuesfrom a well and including perforated means for introducing the oil intothe lower portion of the tank for passage of the oil through the waterto remove well water and foreign matter therefrom, a precooling unithaving means of communication with the tank for receiving clean oiltherefrom, a refrigeration unit having communication with the precoolingunit for receiving the oil therefrom, and means for by-passing gasesfrom the pipe line, tank and the communication means between the tankand the precooling unit for passing said gases to the refrigeration unitto prevent the precooling unit from becoming gas locked.

3. A method of treating crude oil to retain the natural volatile gasestherein consisting in introducing oil to a dehydration unit for removingwell water and other foreign matter therefrom, conveying the clean oilfrom the dehydration unit to a pre-cooling unit, conveying the oil fromthe pre-cooling unit to a refrigeration unit, conveying the oil from thebottom of the refrigeration unit to storage, by-passing gases liberatedfrom said, oil in advance of the pre-cooling unit to prevent the latterfrom becoming gas locked, and introducing the liberated gases into thetop of the refrigeration unit to cause absorption thereof with the oiltherein.

4. The process of treating oil which comprises passing the oil through awashing chamber, conducting the oil from said chamber through aprecooling chamber, passing the oil from the precooling chamber througha refrigeration chamber, and conducting gases from the top of thewashingchamber into the top of the refrigeration chamber.

5. In apparatus for treating oil, a washing chamber, a pre-coolingchamber connected with the washing chamber to receive the oil therefrom,a refrigerating chamber, a conduit for conducting the oil from thebottom of the cooling chamber into the top of the refrigerating chamber,and a conduit connecting the top of the washing chamber with the top ofthe refrigerating chamber for conducting gases from the former into thelatter.

GUSTAV DE BRETTEVILLE.

